CDC Issues Advisory with Interim Guidelines for Prevention of Sexual Transmission of Zika Virus

The Centers for Disease Control and Prevention (CDC) issued an “Interim Guidelines for Prevention of Sexual Transmission of Zika Virus” health advisory on Feb. 23, 2016. Pennsylvania’s Department of Health (DOH) forwarded CDC’s alert to Pennsylvania physicians subscribed to receive its PA Health Network (PA-HAN) alerts.

The CDC and state public health departments are investigating 14 reports of possible sexual transmission of the virus, including several involving pregnant women. Read the CDC’s news release on the issue.

The CDC reports that:

  • In two of these new suspected sexual transmission events that have been investigated to date, Zika virus infection has been confirmed in women whose only known risk factor was sexual contact with an ill male partner who had recently traveled to an area with local Zika virus transmission; testing for the male partners is pending.
  • For four additional suspected sexual transmission events, preliminary laboratory evidence (IgM antibody test) is available for the women, but confirmatory testing is still pending.
  • For eight suspected events, the investigation is ongoing.
  • In all events for which information is available, travelers reported symptom onset within two weeks prior to their non-traveling female partner’s symptom onset.

Since the reports suggest that sexual transmission of Zika virus is more likely than previously considered, the CDC issued its advisory to stress the need to adhere to current recommendations for preventing sexual transmission of Zika virus, particularly for men with pregnant partners. The CDC expects to update its guidelines as more information becomes available.

Recommendations for men and their pregnant partners

Men who reside in or have traveled to an area of active Zika virus transmission who have a pregnant partner should abstain from sexual activity or consistently and correctly use condoms during sex for the duration of the pregnancy. Pregnant women should discuss their male partner’s potential exposures to mosquitoes and history of Zika-like illness with their health care provider; providers can consult CDC’s guidelines for evaluation and testing of pregnant women.

Recommendations for men and their non-pregnant sex partners

Men who reside in or have traveled to an area of active Zika virus transmission who are concerned about sexual transmission of Zika virus might consider abstaining from sexual activity or using condoms consistently and correctly during sex. Couples considering this personal decision should take several factors into account.

Most infections are asymptomatic, and when illness does occur, it is usually mild with symptoms lasting from several days to a week; severe disease requiring hospitalization is uncommon. The risk for acquiring vector-borne Zika virus in areas of active transmission depends on the duration and extent of exposure to infected mosquitoes and the steps taken to prevent mosquito bites. After infection, Zika virus might persist in semen when it is no longer detectable in blood; studies to determine the duration of persistence in semen are not yet completed.

Accumulating evidence of sexual transmission suggests that exposure to Zika virus includes unprotected sexual contact with a symptomatic male partner who resides in or has traveled to an area of active Zika virus transmission. The CDC says that Zika virus testing is currently recommended to establish a diagnosis of infection in exposed persons with signs or symptoms consistent with Zika virus disease, and may be offered to asymptomatic pregnant women with possible exposure to Zika virus.  However, the CDC cautions that interpretation of results is complex, and health care providers should contact their state, local, or territorial health department for assistance with arranging testing and interpreting results.

The CDC does not recommend testing exposed, asymptomatic men for the purpose of assessing risk for sexual transmission at this time. Sexual transmission of Zika virus from infected women to their sex partners has not been documented, nor has transmission from persons who are asymptomatically infected. Sexual transmission of many infections, including those caused by other viruses, is reduced by consistent and correct use of latex condoms.

Stay up to date on the latest news, guidance, and recommendations, on PAMED’s Zika webpage.